Stair structure



Jan. 17,1933. J, FRICK 1,894,463

STAIR STRUCTURE Filed Jan. 2l, 1932 2 Sheets-Sheet l INVENTOR.

ATTORNEYQS'.

Jan, l7, 1933. J. FRlcK STAIR STRUCTURE Filed Jan. 21, 1952 2 Sheets-Sheet INVENTOR.

ATTORNEYQS.

Patented Jan. il?,Y 1933 UNITED STA `J'ULIUS FRICK, OF MILWAUKEE, WISCONSN STAIR STRUCTURE f vApplication filed .Tanuary 21, 1932. Serial No. 587,947;

This kinvention relates in general to improvements in the art of constructing stair-- improved stair structure which may be constructed of concrete or other moldable plastic material. Y y v Another object of the invention is to provide a sectional stairway construction composed of individual tread elements which may be readily manufactured and assembled.

fr A further object of the invention is to pro- 1.fvide improved stairs which are strong, fireproof, and leakproof in construction, and Y Vwhich present anneat and highly finished appearance. Y l Still another object of the invention is to 20S provide'- a reinforced stair tread structure especially adapted for usein assembling comptct stairways in large oiiice buildings or the li e. l

Another objectof the invention is to provide an improved stairway structure-vof the type wherein one side may be interlocked with a wall while the other yside may be left open. A further object of the invention is to provide improved structure for rigidly con- 303 necting. the ends of stairsor stair sections to the Aadjacent floors 'orplatforms l Y Still another object of the invention is to provide an improved end tread for ysectional stairs, which' is especially applicable to the 35" adjoiningupper and lower ends of reversely Y directed stairways extending upwardlyand downwardly kfrom a common platform e or floor. i

Another object of the invention is toV pro- 40 vide various other improvements in the details of construction and in the mode of manufacturingsectional stairways, whereby Va durable and attractive assembly may be produced at minimum cost.

These and other objects and advantages will be apparent from the following detailed description. ,4 A clear conception of an embodiment'of K the several features y'of the invention, and of "o the method of constructingand of assembling sectional stairs built in accordance with the improvement, may be had by referring toV the drawings accompanying and forming a part of this specification in which like reference characters designate the'same or similar parts in the various views:

F'g. l is a top View of a pair of adjacent oppositely directed stairway portions extendingupwardly and downwardly from a common platform;

Fig. 2 is aside elevation of the stair assembly shown in Fig. l, the forward supporting wall having been omitted;

Fig. 3 is ia top View of the special tread used at the adjacent ends of oppositely directed .G5

stair` sections, and of one of the end blocks; Fig. 4 1s a front view of the special tread and end block of Fig. 3;

Fig. 5 is a transverse vertical section through the special tread, taken on the line H 5 5 of Fig. 4; v

Fig. 6 is a transverse vertical section through the special tread, taken on. the line 6-6 of Fig. 4;

Fig. 7 is a part sectional top view of one. '3

ofthe intermediate standard treads, and of one of the end fniish blocks;

Fig. 8 is a front view of thestandard tread and block-of Fig. 7

Fig. 9 is a transverse verticalV section through the standardtread, taken onV the line 9`-9-ofFig.8;and 'f f l.

Fig. 10 is an end view of the standard tread and end block. Y i v lVhile the invention has'been shown and described herein as `being specifically applied to a sectional-stairway wherein oneend ofv each section is embedded in an adjacent wall,

or' cd it should be understood that-some of the features are more generallyl applicable to stairs either ofthe type wherein both ends of the treads are vembedded in walls, or of the type Vwherein both'sides vof the stairway areopen lowermost of the individualy treadslQ., a

special end tread 14 coacting with the uppermost of the individual treads 12, and a Vspecial double-length intermediate tread 15 coacting with the upper and lower treads 12 of the adjacent stair groups or sections. End finish blocks 16 coact with the end portions of the treads and are embedded with the tread ends,

in concrete walls 17 as shown in Fig. 1, so that a desirable base ledge is formed by the exposed ends of the blocks 16. The treads 12,

13, 14, 15 and the blocks 16 are preferably formed of concrete or other moldable material having lire and water-proof characteristics.

The individual treads 12 are preferably of identical construction, and each of these adjoining tread, and if the treads are to be used in open stairways, the tongues 18 and grooves 19 are preferably formed of less length than the treads 12 so that they will not be visible at the exposed ends of the treads when assembled. Each of the treads 12 may be provided with one or more longitudinal reinforcing elements or bars 2O and with one or more transverse through openings or holes l 21. During assembly of the treads 12, they are strung in succession upon inclined assembly rods 22 which pass through the holes 21V and are provided with end clamping nuts '23 for forcing and retaining the adjacent treads in intimate contact with each other.

The lower end tread 13 is provided with a groove 19 at one edge, adapted to receivethe tongue 18 of the lowermost tread 12, and has a groove 24 along its opposite edge adapted to interlock with the concrete ofthe lower floor 25. The tread 13 is also reinforced by one or more bars 20, andthe lower end of the stringer rod 22 is embedded in the tread 13. Y v

The upper 'end tread 14 is provided with a tongue 18 at one edge, adaptedxtocoact with the groove 19 of the uppermost tread 12, and

has a groove 24 along its opposite edge adapted to interlock with the concrete of anupper floor 26. The tread 14 is likewise reinforced by means of 'one or more bars `20, and the- Y upper end of the Stringer rod 22 and the clamping nut 23 coacting therewith, are normally embedded in the concrete of the floor 26.

Y The intermediate tread 15 is shown in detail in Figs.l3, 4, 5 and, and substantiallyl comprises a set of special treads 13, 14 formedy integral with each other and disposed endvto end and with their tread surfaces 27-lying V in thesam'e plane. The tread 15 has a tongue 18`eXtending along substantially one-halfofl one edge, adapted to interlock with the edge groove of the uppertreacl 12 Vof the flower stair section; and also has a groove 19 eX'- tending along substantially the other half of the saine edge, adapted to interlock with the edge tongue of the lower tread 12 of the upper stair section. The entire opposite edge of the intermediate tread 15 is provided with a groove -24 adapted to interlock with the concreteof a platform 28. The tread 15 may likewise be reinforced by bars 20, and the stringerrods 22 of the upper and lower stair Asections colactwith the intermediate tread 15 as clearly shown in Figs. 1 and 2.

The" end finish blocks 16 are formed as shownin Figs. 3 to A1(,)inclusive, and are normally embedded in the concrete ofthe walls 17as indicated in'l Fig-(1,. so thatgonly about one inch of the blocks protrudes beyond the wall surface. vThis projecting portionof the blocks may subsequently be -dressed to prof l/Vhile onl two ad'oininor stair sections have y n c been shown, it willbeunderstood that number of successive` sections may be utilized, and that the length andwidth of these sections maybe yvaried as desired. i

From the foregoing description, itwill be apparent that the individual treads 12, 13, 14,15 `may be readily constructed of concrete or the `like and subsequently assembled toVV produce stairways of any desiredlength, either open, or partially'ienclosed, 'or Ecornpletely enclosed. The treadsare all 'ofstand-V ard height from one treadsurfac'e to the" next, and the tread surfaces are all 'of 'the same breadth measured in the direction of the stairway, thereby maintaining Vcoiistaint in -V clination of the Stringer rods v22. Y After the treadsV have been assembled, the walls lland floors may be cast to maintain the assemblagein final position. lThe tongue and `,f jroove connections between the successive treads, not Y only produce "a firm' interlock, lbut `also pro` vide fire and waterproof joints.- The treads 12 may be formedinthe samefor similarl molds, andare interchangeableV with each other. The lower faces ofthe treads 12 'are parallel'to the vstriiigerholes, thus presentinga neatapp'earan'ce at the bottom `f the "as-gA sembled treads. The structurec'anob'viousV ly be manufactured and assembled at ,relattively low cost, and they assemblage is strong, durable and of highlyvnished appearance.

It should be understood that it is not :del

siredfto limit theinvention tothe efx'aet d e: 'tails of construction hereinv shfown'ad d'e'-,` scribed, for various modifications within theV It is claimed and desired to secure tongues and grooves adjoining said faces, and elongated connecting elements extending through said treads transversely of said tongues and grooves.

2. In a stair structure, a series of individual treads formedv of moldable material and each having a tongue at one edge and a l groove of similar contour at the opposite edge portion thereof, and means extending directly through all of said treads for connecting the successive treads to maintain the adjoining tongues and grooves thereof in interlocked relationship.

3. In a stair structure, a series of identical treads each having a tongue interlocking with a groove of an adjacent tread, a special tread interlocking with one of said iirstmen tioned treads, and rneansextending directly through all oii said treads for connecting said treads to maintain them in interlocked relationship.

4l. In a stair structure, a series of'identical treads each having a tongue interlocking with al groove of an adjacent tread, special upper and lewer end treads interlocking respectively with the upper and lower of said identical treads, and means extending directly through all of said treads for connecting the same to maintain them in interlocked relationship.

5. In a stair` structure, ,a series of identical treads each having a tongue interlocking with a groove of an adjacent tread, special upper and lower end treads interlocking respectively with the upper and lower of said identical treads, andelongated elements extending through said identical treads and into said special treads.

6. In a stair structure, two adjacent series of identical treads, directly interlockable with each other, a single intermediate tread of approximatelyV double the length of one of said identicaltreads coacting with4 the upper and lower end treads of said series, and rod members connecting said intermediate tread with said upper and lower end treads.

7. In a stair structure, two adjacent series of identical treads, a single intermediate tread of approximately double the length of one of said identical treads interlocking with the upper and lower end treads of said series,

with the adjoining treads, and a rod member passing directly through all of said treads in the same direction.

10. In a stair structure, a plurality of treads having alined inclined holes extending transversely therethrough, each of said treads having its opposite ends formed for direct interlocking engagement with the adjoining treads, and a straight rod member extending through said alined holes.

11. In a stair structure, a pluralityof edgewise cooperable treads having alined straight ,holes extending entirely therethrough, and a straight rod member extending through said holes and disposed parallel to the direction or extent of the assembled stairway.

l2. In a stair structure, a plurality of edgewise interlockable treads having alined straight inclined holes extending Ventirely therethrough from the lowermost to the upper portion thereof, and a straight rod member extending through said holes and disposed parallel to the direction of extent of the assembled stairway.

.In testimony whereof, I affix my signature.

JULIUS FRIGK.

and Stringer rods secured'to said intermedil ate tread and extending through the treads of said series.l

8. In a stair structure, a plurality of treads each 'formed for direct interlocking engagement with the adjoining treads, and a rod47V member connecting all of said treads and exa tending therethrough in a direction parallelr to the assembled stairway. y

9. In a stair structure, a plurality oli-onepiece treads each provided with a tongue at one edge and a groove at its opposite edge formed for direct interlocking engagement 

